Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.
Living cells produce a series of catalytic agents the purpose of which is to accelerate the reactions that occur under the conditions that occur in living matter. These biocatalysts are called enzymes They are proteins that speed up certain chemical reactions without being themselves affected by the reaction. They are now manufactured on a large scale and used for many purposes.
Enzymes are widely used in industrial processes, food processing and manufacturing, and in household products. For example they have been used in such household products as laundry detergents to assist in digestion of soiling of biological origin, in dishwashing detergents to assist in digestion/removal of food scraps. They are widely used in manufacturing industries for example in tanning of leather, dewooling of fleeces, manufacture of cheeses, of paper, of bread and in many other industries. Enzymes have also been employed in hospitals, medical, dental practices, and the like to assist in digestion and removal of biological contamination from surgical instruments and paraphernalia.
A number of assay methods have been proposed to determine the presence of an enzyme, and to quantify its activity. Generally this involves the conduct of sophisticated and always time consuming chemical assays which need to be conducted by skilled analysts. Annexed hereto and marked annexure 1 is a typical method for determining the proteolytic activity of protease and based on a USP method. The method requires a spectrophotometer and other apparatus, reagents (some of which must be made up fresh daily) and a skilled technician to perform the work. The procedure cannot be completed in less than about 2 hrs.
It would be useful to have means for quickly detecting whether or not a particular enzyme or class of enzymes was present in a sample of a composition. It is also often important to know the degree of activity of one or more enzymes in a system and it would be desirable to have a relatively quick, simple and inexpensive assay method, and preferably one which could be conducted by relatively unskilled persons.
In recent years a large number of test strips have been developed which employ immobilized enzymes to detect an analyte of interest in a sample, for example to measure glucose in a blood sample or of blood in fecal material. Many of these devices require complex amperometric measuring devices to provide a read out and are of relatively complex and costly construction. While such devices employ enzymes, they do not provide a measure of the activity of an enzyme nor an indication of its presence in an analyte.
It is an object of the invention to provide a means of enzyme detection and/or activity assay which avoids or at least ameliorates one or more disadvantages of the above discussed prior art, or provides a commercially useful alternative.